1. Field of the Invention
The present invention relates to an electric connector to connect a central processing unit and a motherboard, and more particularly to an electric connector driving by a cam.
2. Description of the Prior Art
A conventional electric connector to connect a central processing unit and a motherboard comprises an insulation base and a cover. The cover has a plurality of upper receiving holes, and the insulation base has a plurality of lower receiving holes corresponding to the upper receiving holes. Each lower receiving hole is provided with a socket terminal. A driving device is connected to the cover and the insulation base and used to open or close the electric connector. When the electric connector is in a disconnection state, the pins of the CPU chip module are not contact with the corresponding socket terminals. After that, the driving device is operated to move the cover toward one side of the insulation base for the pins of the central processing unit to electrically contact with the socket terminals in the lower receiving holes. At this time, the central processing unit is in a closed state. When the driving device is operated to move the cover toward the other side of the insulation base, the pins of the central processing unit disconnect from the socket terminals in the lower receiving holes. The central processing unit is in a disconnection state.
The driving device of the conventional electric connector is an eccentric driving cam. The eccentric driving cam includes a first post, a second post, a third post and a forth post from top to bottom. The radius of each post is reduced in turn. The first and second posts are coaxial, and the third and fourth posts are coaxial. The two axles are interlaced a certain distance to form the eccentric cam, so that the insulation base is driven to move relative to the cover. One side of the first post is integrally formed with a stop portion. The stop portion has two stop surfaces at two sides thereof. The stop surfaces are parallel to the sliding direction of the cover. The cover has a limit recess thereon corresponding to the stop portion. The limit recess has two limit surfaces at two sides thereof. During use, the stop portion of the eccentric driving cam mates with the limit recess. When the eccentric driving cam is turned to be an open state or a closed state, the limit surfaces are used to stop the stop portion in order to stop the eccentric driving cam.
The eccentric driving cam of this electric connector can be used to connect the CPU chip model and the electric connector or disconnect the CPU chip module and the electric connector. However, the limit surfaces of the cover bear all the driving force. When the force is applied too much, the cover may be broken off. This is not beneficial to the life span of the product.
Besides, the stop surfaces are parallel to the sliding direction of the cover. When the eccentric driving cam is turned to be open or closed, the direction of the applied force and the sliding direction of the cover are not the same. It needs much torsion force to connect the electric connector and the CPU chip module. Accordingly, the inventor of the present invention has devoted himself based on his many years of practical experiences to solve these problems.